Door for electric furnaces.



F. T. SNYDER. noon FOR ELECTRIC runmcas.

APPLICATION FILED OUT. '28, 1912. 1,100,994, Patented June 23, 19m

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F. T. SNYDER. DOOR FOR ELECTRIC FURNACES. APPLICATION rum) 0m. 2a, 1912.

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fl?RIEDERICK T. SNYDER, OF OAK PARK, ILLINOIS.

DOOR FOR ELECTRIC FURNACES.

Specification of Letters Patent.

Patented June 23, 1914.

Application filed October 28,1912. .Serial No. 728,089.

To dll whom it may concern:

Be it known that I, FREDERICK T. SNY- DER, citizen of the United States, residing at Oak Park, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Doors for Electric Furnaces, of which the following is a full, clear, concise, and exact description.

My invention relates to doors for electric furnaces, and its object is to provide a door of simple construction, which will act as a plug to close the charging opening to the furnace aiid which can be adjusted to accurately fit such opening.

One feature of my invention consists in the construction of the door itself.

Another feature relates to the manner in which the door is mounted upon its hinges, whereby the door, as it is swung open, may also be rotated about a vertical axis and may thus always be maintained in such position that the outer face of the door is turned toward the workman who opens the door.

My invention also provides means wherebythe door may be adjusted upon its hinges soas to be brought nto true alinement with the charging opening.

Stillranothcr feature relates to the structureof the hinge and to the means of mounting the same.

'My invention also contemplates means for securing the door in its closed position.

These and other features of my invention may be more readily understood by reference to the accompanying drawings, in which- Figure 1 is a side elevation of an electric furnace provided with a door embodying my invention; Fig. 2 is a section on the line 2-2 of Fig. 1; Fig. 3 is an enlarged, frag .mentary view showing the means for securing the door in its closed position. Fig. 4 is a bottom plan view of the structure shown in 'Fig. 3; Fig. 5 is a fragmentary, enlarged detail view of one of the two similar bearings for the trunnions which" form a pivotal mounting for the door; Fig. 6 is a plan view of the furnace shown-in Fig. 1, two of the positions which the door may assume in its open position being indicated in dotted lines upon opposite sides of the furnace;

and Fig. 7 is an enlarged, vertical section of one of the two similar ad ustable co ne bearings of the doorhmge.

Similar letters of reference refer to similar parts throughout the several views.

The furnace 1 is provided withan inwardly tapering-charge opening 2 adapted to be closed by a correspondingly tapering door 3' which acts as a plug to close said opening. 'Both the opening 2 and the door 3 are of circular cross-section.

The door 3 comprises an outer metallic casting or frame 4 having a peripheral flange 5 provided with an inwardly'extending annular extension. Fitting the inner face of-the frame a is a plug of fire-proof material, said plug havingthe form of a frustum of a cone. Said plug is'made up of a number of bricks 6, such bricks tapering inwardly, as indicated in Fig. 2, and also tapering toward the longitudinal center of the door, as indicated in dotted lines in Fig. 1. Eachof the bricks 6 is cut away at its inner corner, as indicated in Fig.2, so that when-said bricks are assembledthe inner end of'the-assembled brick-work ofthe door has formed therein'a central cavity 7. Said brieks are held in their assembled relation by a T-bolt 8, which extends through a clamping-plate 9' in the bottom of the cavity 7. The end of the bolt 8 extends through the frame 4 and is fitted with a nut 9. After the bricks are'clamped in their assembled rclation,=the cavity 7 is filled with fire clay 10.

The door 3 is pivoted to rotate upon its hinge .11, such rotation being on a vertical axis. To thus pivot the door the frame 4 is provided with diametrically opposite trunnions 12, journaled in bearings 13, carried by the upper and lower arms 14, '14 of the hinge 11. The bearings 13 are in the form of eccentric socket-pieces which are clamped to the arm 14, 14 by means of the U-shaped bolts 15. By adjusting the eccentrics 13 the central, vertical axis of the door can be adjusted either inwardly, outwardly or laterally, or, more broadly speaking, in any horizontal direction, and thus the door, after being properly adjusted vertically, in

the manner presently to be described, can

be brought into exact alincment witlv the opening 2.

The hinge 11 comprises the vertical post 11 and the two horizontal arms 14, 14. Mounted nearthe upper and the lower portions of the furnace are brackets 16, 16, in which are threaded the pins 17, 17. Said vertically to bring the door 3 into proper alinement with the charging opening.

Pivoted upon the end of the arm 14 by a bolt 19 is a latch 18 which is adapted to be swung by its operating handle 20 be neath a hook 21 and thus to secure the door in its closed position. It is -obvious that by means of washers 22 about the bolt 19 the latch 18 can be so adjusted inwardly or outing at eac ide of the pout tab;

wardly as to accurately fit beneath the hook 21 and hold the door tightly closed.

Surrounding the charge opening 2 is self sustaining circular arch ring 22 of refractory brick. By having the door of circular cross-section, I am enabled to make this door arch circular and thus particularll'y" 7.v

adapted to resist lateral pressure from a directions tending to close up the door open ing, especially pressure due to the expansion of the furnace lining by great heat.

The arch 22 tapers toward the center, thus providing a large opening at the outside for moving the handles of rabbles and other furnace tools and a small opening at the inside, where the movement of the tools is less. This form of opening reduces to a minimum the radiation of heat through the opening. These plug doors are mounted on diametrically opposite sides of the furnace, so that the common axis of the doors will pass through the axis of the electrode 25. By opening both doors, this arrangement of the doors permits the white-hot electrode being viewed from one door against the dark outside background visible through the other door. Both doors are placed at equal distances from the furnace spout 24 to em able the condition of the inner furnace lin- (lbsi'vtid from the opposite door.

It is important, in the operation of electric furnaces, that the furnace door closely fit the charging opening, not only to revent the escape of the heat from the urnace, but to 'close the furnace against access of the outside air, since otherwise an oxidizing atmosphere may be produced in the furnace injurious in its effect upon the charge being smelted. My invention is designed, therefore, to provide a door which acts as a close-fitting plug. Moreover the brickwork of the door being subjected to inis turned away from a workman when he has occasion to open the furnace door.

In furnace doors as heretofore commonly constructed, namely to slide up and down, it has been necessary to have counterweights to balance the weight of the doors so as to permit of easy movement. With my type of pivoted door, nocounterweight is required. In a tilting furnace with sliding doors, inconvenience is caused by the swing of the door-counterweights when the furnace is tilted. With my type of hinge mounting the hinges can be mounted on the side of the door which will be above when the furnace is tilted, so that the doors will swing shut automatically when the furnace begins to tilt and thus protect the workmen tapping the furnace from the escape of heat from the door openings.

I claim 1. The combination with a furnace having an inwardly tapering door opening, of a tapering refractory plug adapted to enter and close said opening, and a hinge for said plug providing means for moving said plug into and out of said door opening and also for rotating said door upon an axis independent of the axis of the hinge. v

2. In a furnace door, the combinationof a plug of refractory material, an outer frame to which said plug is secured, a hinge comprising a pivoted post having two arms, and means for pivoting said frame between said arms.

3. In a furnace door, the combination of a plug of refractory material, a hinge comprising a pivoted post having two arms ex-.

to move 1n and out of said door opening and also to rotate on a vertical axis.

6. In a furnace door, the combination of a plug of refractory'material, a hinge-member comprising a posthaving two arms extending from near the opposite ends thereof, means for pivoting said post at its opposite ends, said means being adjustable to adjust said hinge-member, and means for adjustably pivoting said plug between said arms. i

7. A furnace door comprising a circular outer frame; a tapering plug having the shape of a frustum of a cone, said. plug being formed of interchangeable bricks of refractory material and each of said bIlCkS being cut away to provide a'central cavity in said plug; a clamping plate in the bottom of said cavity; and a clampin bolt extending through said clamping p ate and said outer frame.

8. In a furnace door, the combination of a plug of refractory material, an outer frame to which said plug is secured, a hinge comprising a vertical, pivoted vpost having an upper and a lower arm, and means for pivoting said frame to said arms.

9. In a furnace door, the combination of a plug of refractory material, an outer frame to which said lug is secured, a hinge comprising a vertica, pivoted post having an upper and a lower'arm, vertical trunnions extending from said frame, socketpieces ,having eccentric sockets therein constituting bearings for said trunnions, and means for adjustably securing said socketpieces to said arms.

10. In a furnace door, the combination of a plug of refractory material, a hinge-member'compr singa vertical post having an upper and a lower arm, means for pivoting said post at its opposite ends, said means being adjustable to vertically adjust said hinge-member, and means for adjustably pivoting said plug betweensaid arms.

11. In a furnace door, the combination of a plug of refractory material, a vertically pivoted hinge-member comprising a vertical post having an upper and a lower arm, means for pivoting said plug between said arms, a latch pivoted upon the outer end of means for tilting the same, said furnace being rovided with a door opening and a pouring spout, of a door hinged at that side.-

of the door opening farthest removed from said spot, whereby said door tends to close by gravity when the furnace is tilted forwardly.

14. The combination with an electric fur- I nace having a pouring spout and an electrode located in the vertical plane through the axis of said spout, of doors on opposite sides of said furnace, said doors having a common axis and being so spaced from said spout that the common axis of said doors passes through the axis of said electrode perpendicularly to the vertical plane through the axis of said spout.

In witness whereof, I hereunto subscribe my name this 26th day of October, A. D., 1912.

FREDERICK T. SNYDER.

Witnesses:

ALFRED H. MOORE, MCCLELLAND YOUNG.

copies of this patent may be obtained for ave cents each, by addressing'the Commissioner of Patents, Washington, D; 0." 

